Door knob



FIG. 1 is a perspective view of a door knob.

FIG. 2 is a top view thereof.

FIG. 3 is a bottom view thereof.

FIG. 4 is a first side view thereof; and,

FIG. 5 is a second side view thereof.

The dashed lines in the views form no part of the claimed design and are provided as illustration aids. 

CLAIM The ornamental design for a door knob, as shown and described. 